The PIT has advanced from being just a large-screen dual head-tracked stereo display to an almost -ready-for-prime-time two user work environment during this reporting period. Porting the CORWIN application to the PIT, work done by entering graduate student Tim Preston, validated the ease of porting for the visual aspects of an application and helped us to develop a framework for returning user picking parameters to the application. Graduate student Kevin Arthur has refined and improved the software library that controls the PIT and provides the interface between applications and the PIT. The library is being picked up and used by others within our laboratory in applications outside this project. This provides valuable user feedback on both functionality and quality of the documentation in preparation of our making the software public in the next reporting period. Specific improvements made during this reporting period include: - Application control panels are enabled on PIT laptop computers - PIT control panels for display on the laptops were implemented in Tcl/Tk - Pointing and 3D picking functions were implemented - Buttons, dials, 6 DOF handheld pointing devices and a PHANToM were integrated into the system - Magnetic tracker (2 heads and 2 hands) speed and robustness were improved via integration of new tracking and control SW (developed in another project for universal use in the lab) - System robustness was improved - Initial work was done on decoupling display and simulation processes for improved responsiveness to user inputs, particularly head motion.